Switching device



Aug. 14, 1934.

A. F. ERICKSON `SWITCHING DEVICE 'Filed Nov. 5o. 1931 .[75 Vt 02 ,4e THae Efe/CKJON ArrozNe-HS' Patented Aug. 14, 1934 Y UNITED STATES SWITCHING DEVICE Arthur F. Erickson, San Francisco, Calif., as-

signor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application November 30, 1931, Serial No. 578,054

21 Claims.

This invention relates to improvements in thermostatically controlled switches, and finds valuable use in systems for automatically controlling heat regulation, one example of such use being disclosed in my copending application for Fuel control systems, Serial Number 578,053 filed November 30, 1931.

Among the objects of the present invention are: to provide a unit which includes a thermostatically controlled element, which element controls a plurality of switches; to control the switches to open a certain one only after another one is closed, and to lock this last mentioned switch against return to a normal position while a control and circuit-making element moves to break the circuit. Features of the invention include the broader aspects of the disclosure, as well as the details of construction including means for latching, as well as the means for releasing a latched contact-making element.

Objects, features and advantages of the invention will be set forth in the description of the drawing forming a part of this application, and in said drawing Figure 1 is a vertical section through the thermostatically controlled stack switch structure; and

Figure 2 is a face view with the cover removed, showing the face view of the switches.

'In this embodiment of the invention the device comprises a suitable housing 1 having a tubular extension 2 to one end of which a helically coiled bimetallic element 3 is secured. The opposite end of this element is secured to a rod 4 which passes through the coil and is rotatably journaled in the extension 2, and which passes through the extension, through an insulating block 13 within the housing, and through a bushing held by this insulating block. The end of this rod terminates within' the housing and is threaded as at 5. Arranged on this rod within the housing are toothed wheels respectively designated 7--8, and these wheels are secured by nuts 6 for rotation with the rod. Washers and disks 9 properly insulate the ratchet wheels from the rod. Mounted also within the casing, and secured by one end to an extension of plate 11, in turn secured to the block 13, is a control element 10 which has a free end engageable with the teeth of the wheel 7. The plate 11 has a suitable binding post for circuit connection in the system in which it is used. Also upon this plate is secured a contact arm 14, the arm being arranged in opposition to the control arm as shown. The arm 14 carries a contact pin 15 on itsfree end, which pin passes free- (Cl. 20G-138) ly through an aperture 16 of the element 10. A plate 17 is also attached to the block 13, and has a suitable binding post, and has attached thereto spring arm 18 which is provided with contact disk 19 cooperative with pin 15 to close the circuit. 60 The elements 15-19 constitute a switch. The element 10, in this instance, is parallel with the arms 14, 18, and is arranged between them. The manner of controlling the element 10 by the toothed wheel 7 is substantially identical with the 65 disclosure of Patent No. 1,768,892, and in itself forms no part of the present invention. This switch 15-19 is normally closed, that is, is closed when the ribbon 3 is substantially cold.

Attached to the block 13 are a pair of bars 70 21 to which is attached by one end a second control element 20. One oi the bars is provided with or connected to a suitable binding post. The element `20 carries two contact pins one at each opposite side, respectively indicated by nu- 'l5 merals 22-23. The contact pin 22 cooperates with the contact disk 24 carried at the free end of spring arm 25, which arm is attached at its opposite end to plate 26, also mounted on insulating block 13. Contact 23 cooperates with con- 80 tact disk 27 carried by the resilient arm 28, the opposite end of which arm is secured to plate 29, also mounted on block 13. Each of the plates 26 and 29 is provided with a suitable binding post. Upon an outward extension of the plate 29 is attached a spring 30 which has at its free end, an angularly related portion 31 the end of which is bevelled as at 32. The portion 31 is adapted to be frictionally engaged by the outer end of the arm 28 when this arm is forced against 90 the extension 31 by means of the control element 20. A friction lock is thus provided which secures the spring arm 28 in the position mentioned, while the arm 20 moves in the opposite or clockwise direction, due to the cooling of the spiral bimetallic element 3.

In order that the arm 28 may be released to again assume `the position shown in the drawing, the element 20 is provided with a hook 33, which engages an insulating plate 34 secured flatly 100 against one face of the-arm 28. In this instance, the release takes place only after contacts 23 and 27 have been separated. Pin 22 and disk 24 are viewed as constituting a switch or contact. Pin 23v and disk 27 also constitute a switch or 105 contact. A

The character of the control means necessary for use with the typer oiswitches herein used, differs radically from means used for th`e control' of mercury tube switches. ii feature of this in' 110 .clockwise direction.

vention is the control of the movable contact type of switch (as distinguished from the mercury tube switch), overlappingly on temperature rise, and non-overlappingly on temperature fall in the manner below described. so that switch 23-27 is. on temperature rise, closed before switch 22-24 opens, and so that on temperature fall 23-27 is opened before 22-24 closes, and so that the arm 28 is released from its latched position' after switch 23-27 opens. Another featiu'e of the invention relates to the control of three switches by a common control element, to-wit by the rod 4 through its disks 8 and 9. A specitlc feature of the invention is the latch structure.

The terms switches of the open non-fluid type or open contact type are used principally to disfrom switches of the mercury tube type in which the contacts are enclosed in a sealed tube and in which the movable switch element is a liquid ora gas. l y

'I'he operation of the device is as follows: Referring to Figure 2 which represents a position of the parts when the thermostatic element 3 is cold. When this last mentioned element is heated, the rod 4, in this instance, rotates in antias indicated by the arrow. Both elements 10 and 20 are moved in direction of rotation. After a certain amount of movement has taken place, 23 engages 27, and on concontact is made at 23 27, after which continued motion of the arm 20 breaks the contact 22-24.

While the arm 20 is moving in the manner mentioned, arm 10 is also moving and control element 10 iinally engages spring arm 14 to separate elements 15-19 and open the switch. Various adjustments can be madefbut in some instancesswitch 23-2'7 may close before switch 15-19 opens. On temperature fall (in which instance the rod 4 rotates in clockwise direction moving the disks in the same direction) the arm 10 is actuated to substantially immediately close switch 15-19. In this embodiment also the switch 23-27 is substantially immediately opened. However, the contact 23-27 is broken left in latched position before the switch 22-24 closes. The arm 28 is while the arm 20 moves away and in this embodiment switch 22-24 is closed before the hook 33 engages arm 28 to unlatch it and permit it to move to the initial position shown in the drawing. Various modifications in the relative movements of the control arms and the latching sequence, etc., may be made without departing from the spirit of the invention. For certain purposes, the control of the switches,goverlapping1y on temperature rise and non-overlappingly on temperature fall is an important feature. See application of this feature in the aforementioned co-pending application.

Continued motion of the rod in anti-clockwise direction, due to temperature rise after switch 15-19 is open and after the arm 28 is latched, merely results ln idling action of the respective control members 10-20 without otherwise changing the position of the movable members of the switches, or without in one instance allowing 15-19 to close, and in the other instance without allowing 23-27. 'I'he same idling action occurs after the switches have reached their opposite control positions. This action is more specifically set forth in Patent No. 1,788,892 above referred to. After the switches are in their con- I claim as my invention: l 1. A device of the class described comprising contact arms, a control element is thermostatically controlled for reverse motion conformably to temperature changes, means for latching the second arm after a predetermined motion given it by said control element, and means by which on reverse movement of the thermostatically controlled means the second arm is released from its latched position.

`2. A device of the class described comprising first and second resilient contact arms, and a control element adapted normally to engage one of the arms and be spaced from the other, means by which the control element is thermostatically controlled, means for locking the second arm after a predetermined motion given it by said control element, and means carried by the control element and operable o n reverse movement of the thermostatically controlled means to release the a'rm from its latched position.

3. A device of the class described comprising first and second movable contact arms, a movable control element as a conductor, means by which the control element is thermostatically operated on temperature change in one direction to assume 'a switch-closed relation with and move the second arm. means for locking the second arm after being moved by the control element and means by which. the control element is adapted after a predetermined amount of reverse motion of the thermostatically controlled means due to temperature change in an opposite direction, to release the second arm from its locked position.

4. A device of the class described comprising rst and second movable contact arms, a movable control element as a conductor adapted to be normally in switch-closed relation with the iirst arm and in second, means by which the control element is thermostatically controlled on temperature change in one direction to assume switch-closed relation with and move the second arm, means for releasably locking the second arm after being moved by the control element, and after the control element assumes switch-open relation with the first arm, the control-element and arms being so related that on reverse motion of the thermostatically controlled means due to temperature change in an opposite direction and after the control element has assumed open switch relation with the second arm, and after said element has assumed switch-closed relation with the first arm, the second arm is released from its locked position, by means controlled by the control element.

with the first arm, and in switch-open relation with the second, means by which the control element is thermostatically controlled on a rise in temperature to engage and move the second arm, means for reswitch-open relation with the leasably locking the second arm after being moved by the control element and after the control element assumes switch-open relation with the nrst arm, the control element and arms being so related that on reverse motion of the thermostatically controlled means due to fallin temperature and after the control element has assumed open switch relation with the second arm, and after said element has assumed switch closed relation with the first arm, the second arm is released from its locked condition, by means controlled by the control element.

6. A device of the class described comprising pairs o! contactarms each having a control element adapted to engage the arms, common thermostatically controlled means adapted to engage and move respective control elements, the control element between one pair of arms being in electrical connection with one of the arms only and the other control element being adapted for electricalcontact connection with either or both of its arms, and means by which one of the arms is releasably latched after movement by its control element, and means operable by the control element for unlatching said arm as said element moves in an opposite direction.

'1. A device of the class described comprising ilrst and second resilient contact arms and a control element as a conductor adapted to normally engage the first larm and be spaced from the second, means by which the control element is thermostatically controlled on temperature rise in one direction to engage and move the second arm, means for frictionally locking the second arm after a predetermined motion of said control element and after separation from the rst arm, the control element and arms being so related that after reverse motion of said control element and separation from the second arm and after re-engagement of the control element with the first arm, said second arm is released from its frictionally locked position by means controlled by the control element, a third switch comprising two normally contacting arms and a control element for separating them, said control element being also operable by said aforementioned thermostatically controlled means, in a manner to open the contact while the first mentioned control element moves to contact its second arm, and on reverse motion Vto separate its arms before said rst mentioned control element separates from its second arm. l

8. A device of the class described comprising first and second contact arms, a movable control element as a conductor, means by which the control element is caused to move in reverse directions in accordance with corresponding temperature changes, means for frictionally releasably latching one of the arms after that arm has been engaged and moved by the control element, and means by which the latched arm is released as the result of motion of the control arm in an opposite direction.

9. A device of the class described comprising first and second contact arms, a movable control element as a conductor, means by which the control element is caused to move in reverse directions in accordance with corresponding temperature changes, means for frictionally releasably latching one of the arms after that arm has been engaged and moved by the control element, said.

means comprising a resilient element having a portion engageable by the arm, and means by which the latched arm is released as the result of motion of the control arm in an opposite direction, said means comprising a hook on the control element.

10. A device of the class described comprising nrst and second contact arms, a movable control element as a conductor, means by'which the control element is caused to move in revers'e directions in accordance with corresponding temperature changes, means for frictionally releasably latching one of the arms after that arm has been engaged and moved by the control element, and means by which the locked arm is released as the result of vmotion of the control arm in an opposite'.

direction, the arms being resilient and being so l biasedand the control element being so related to the arms, that latching takes place after the control element breaks contact with one arm, and.

after the control element has contacted and moved the other arm toward latched position, and

on reverse motion only releases the locked arm after separation from this arm and after the control element has contacted the other arm.

l1. A device of the class described comprising two pairs of spaced resilient arms each having a movable control element, one of the control elements acting as a conductor, means for operating the control elements in reverse directions in accordance with temperature changes of a common temperature responsive means, the conducting control'element being normally adapted to assume a switch closed relation with one of its arms, and move the other arm on a change of temperature in one direction, means for latching this arm after being moved by the control element, said control element being adapted after a predetermined amount of motion due to temperature change in an opposite direction to release the latched arm, and the other control arm being adapted to separate its contact arms when the control element moves in -one direction to cause them to close when it moves in an opposite direction, the arms and control elements being so adjusted that the conducting control element breaks contact with one of its arms only after it has made contact with its latchable arm, and on reverse motion, makes contact with the first mentioned arm only after it has broken contact with the latched arm on a reverse motion, and the other control element being adapted to separate its arms while the conducting control arm is moving toward its latchable arm, and vice versa.

' 12. .A device of the class described comprising an actuator, first and second switches of the nonfluid type, and means associated with the actuator and switches operable for closing the sec-A ond switch prior to opening the first on movement of the actuator in one direction and for opening the second prior to closing the rst on movement of the actuator in the opposite direction.

13. A device of the class described comprising an actuator movable in reverse directions, rst and second relatively stationary contacts, first and second movable contacts of the non-fluid type respectively engageable with the first mentioned contacts, connections by which the actuator reversely moves said movable contacts, and means associated with said contacts for causing the second movable contact to engage the second relatively stationary contact before the first movable contact disengages the first relatively stationary contact when the actuator moves in one direction and for causing the second movable contact to disengage the second relatively stationary contact before engagement of the rst movable contact with the first relatively stationary contact on movement of the control element in the opposite direction.

14. A device of the class described comprising an actuator movable in reverse directions, mst and second relatively stationary contacts of the non-fluid type, a control element for engaging said contacts, means by which the actuator reversely moves said control element. and means associated with the contacts and control element for causing the control element to engage the second contact before disengaging the first contact when the control element moves in one direction and for causing the control element to dlsengage the second contact before engaging the nrst contact on movement of the control element in the opposite direction.

15. A device of the class described comprising first and second switches of the non-fluid type, an actuator for the switches, means associated with the actuator and switches for causing closure of the second switch prior to opening of the first on movement of the actuator in one direction and for opening the second prior to closure of the first on -movement of the actuator in the opposite direction, and means controlling the actuator to move it in either direction to one circuit controlling position and thereafter maintain it in thatposition while the actuator controlling means continues to move in that particular direction.

16. A device of the class described comprising first and second switches of the non-fluid type, an actuator for the switches, means associated with the actuator and switches for causing closure of the second switch prior to opening of the first onvmovement of the actuators in one direction and for opening the second prior to closure of. the first on movement of the actuator in the opposite direction, means controlling the actuator to move it in either direction to one circuit controlling position and thereafter maintain it in that position while the actuator controlling means continues to move in that particular direction, and means for thermally controlling the actuator controlling means, so that closure of the second switch and opening of the first is obtained on temperature rise and opening of tne second and closing of the first is obtained on temperature fall.

17. A device of the class described comprising first and second switches, a control element arranged toA occupy an initial position and requiring force to move it in opposite directions to control said switches, a rotatable member, a thermostatic element connected with the member and adapted to transmit reverserotary motions thereto in response to temperature changes. means associated with the rotatable member and cooperable with said switch control element to move it in either direction to one circuit controlling poi sition and thereafter maintain it in that position while the member continues to rotate in that particular direction, and means associated with the control element and switches for causing the second switch to close before the first is opened on motion of the control element in a direction corresponding to temperature rise and for causing the second switch to open before closure of the first on reverse movement due to temperature fall.

18. A device of the class described comprising first and second switches, a control member arranged to occupy an initial position and requiring force to move it in opposite directions to control said switches. a rotatable member, a thermostatic element connected with the member and adapted to transmit reverse rotary motions thereto in response to temperature a toothed disk movable by the rotatable member and so associated with the control member as to move it in either direction to one circuit control position and thereafter maintain it in that position while the member continues to rotate in that particular direction, and means as sociated with the control element and switches for causing the second switch to close before the first is opened on motion of the control element in a direction corresponding to temperature rise and for causing the second switch to open before closure of the first on reverse movement dus to temperature fall.

19. A device of the class described, comprising, in combination, an actuator movable in reverse directions, a toothed disk controlled thereby, first and second switches, and means associated with the actuator and switches for closing the second switch prior to opening the first switch on movement of the actuator in one direction and for opening the second switch prior to closing the first switchen movement of the actuator in the other direction, said means including a member engageable with the teeth of the toothed disk, in such manner that continued movement of the actuator in the same direction after the switches have been operated, results in the passing of one or more of the teeth of the toothed disk over said member, while the member continues to maintain the particular control positions of said switches. 110

20. A device of the class described, comprising, in combination, first and second switches, an actuator movable in reverse directions, a toothed disk controlled thereby, control means for said switches including a member engageable with the teeth of said toothed disk in such manner that the control means will be moved to one of its switch control positions upon initial movement of the actuator in either direction and will be maintained thereat upon continued movement of the actuator in the same direction, and means associated with the switches and control means for closing the second switch prior to opening the first switch on movement of the actuator in one direction and for opening the second switch before closing the first switch on movement of the actuator in the other direction. l

21. A device of the class described comprising a single actuator movable in reverse directions, first and second switches of the non-fluid type, connections between said actuator and switches for closing said first switch upon initial movement of the actuator in one direction, for opening the second switch upon movement of the actuator in the same direction, for opening the first switch upon initial movement of the actuator in the reverse direction and for closing the second switch upon movement of said actuator in said reverse direction, and means associated with said actuator, switches and connections for delaying opening of the second switch until after closure of the first switch upon movement of the actuator in the first direction and for delaying closure of the second switch until after opening of the first switch upon movement of the actuator in the 145 reverse direction.

ARTHUR. F. ERICKSON. 

